
$error interface Xa satisfies Ya {}
interface Ya => Za;
$error interface Za satisfies Xa {}

$error class Xb() extends Yb() {}
class Yb() => Zb();
$error class Zb() extends Xb() {}

$error alias Xc => Yc;
$error alias Yc => Zc;
$error alias Zc => Xc;

$error interface ReallyBrokenInterface satisfies ReallyBrokenInterface;
$error class ReallyBrokenClass() extends ReallyBrokenClass();